SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb100d9f4255f59cc673e3ef9ac783a48501d4599abf03a3465ffe01c050fd45' 
  AND token = 'UzDlyUD5ybO6+TvzlFZuZaJMpJXonffdDihzps3kEFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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