SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4764db9f68188818e09172c6bf4c730c82baba37e9843e935a9c763fc20ebe75' 
  AND token = 'LcuK6bBja07RWWvQNyD+c6XC8IK5xYEIsxpLDQ4XiTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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