SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6c72d42fa18d504e95af37b359fbb643ec726165fc2c03d82ff736e0b02d2c2' 
  AND token = 'UnWbCc7j6eDU/HNMiu7Oj15Zl3ulwUmLm9xzBNdItM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}