SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '765cb2780a90971216ca01328aadad55bc62103a9bf700c845d278a59dbaa827' 
  AND token = 'Ch45JWdLLZWWTzKN4xYIY4/pHCDp73pO7pqaz1ukqg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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