SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '296079649d2abf6d74639a9d772534cf8bb0e53244c5165a60cb6594f426aff1' 
  AND token = 'BUhG6nqS5aPvjLEl5boS8D+vgomlzgAYti42TUW7wIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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