SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0749c15833f85b65e4ec975c0fa793856d48cb31e5d1ba26bca0d6e7df2435c6' 
  AND token = 'mfVGoghzt+KDBKlgXmvb1YEZPoaRj1JcbOpQ9QI6C3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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