SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b90649c0282646488c521991cd97466984425b688f05afffa2551b11cf80192' 
  AND token = 'c/aeYQiF+AljHWLWUPeu0aS0EQoOuNb9NYeA3Ptemd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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