SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8ecfc69f9097724511194033254019fd3db61fa5bbfbbff40041ebb9be452eb' 
  AND token = 'fGuUBHEOXDK/b+A5/3VaeJRdVmfnqfaEKyfdjQuq0IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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