SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bffbbcf3e94a9fbd5f9fce5c1e19a11fa13bf210d640e76c8f2f8207c258126a' 
  AND token = 'w9K8ymH6uzC4jT2GQbxSrZA5chXTfsWx2AHKdhOV1XM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}