SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f710fe70753778b5fa354b3b088abbb06891a7988231ab387c3c8fa2d5b95985' 
  AND token = 'ROBDnRLp6uV00gyGIoaVTm8NV5hNbCiTgVzBIdNLJ7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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