SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e95c2fd5d47f946bde449b553d29b53f4dd8f1f0ac173a8690687c12f22caef0' 
  AND token = 'A4U+hRoFMlWem/oCvLKJ5hw0UYdEkWchJxHS1lAm598=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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