SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb16bc59ef34dc9283757adecf5762bb61060d85954646e62be9ac51a95dfe27' 
  AND token = 'p0QISMyJf5LaB77zI/x+kD9cmTmX3oL5m3WpO9Glwb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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