SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '404dc84da6103e28e89ba18b20c23d94da4304aff6210f5f95bc486eee5d98c8' 
  AND token = '9iWdglcVf61OMUaZREYvc077m/sQsEKXZppgNdPcrOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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