SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e90f5657596f83965a1310460147ae107adb014e7c9f668c75b86b4c4ed3671d' 
  AND token = 'Tm67YL83bCu9AYZ9K+gpXwylqalJLlhdgl8udhU2/f4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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