SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522b9fd5dfcce37fb65ccaac7efc471149b1ead7bcf488dddf3eaa1077726854' 
  AND token = 'I4r9fYaFW70tyOPpPo378H2wVptGIrugsJaGzSFE06Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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