SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3dcab1afa173b4e69e7415e8b1e9f34af9388009046d0bfaa3779b11e482abf' 
  AND token = '1ywmLoKNr4yoKXbWAqXrn2FpjYQQyRXKxGhsxeckyDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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