SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce460c1239bdbee0d8b974209ef2b07f6d31a5cb9b0afea9108d8175ff9fbef6' 
  AND token = 'l5KYsSjkD4o/KMN7YC08eLk+BDsu4RWN9aw2hhM3nvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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