SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd746c88086887994d067deaa705422203909c376352c866d696915debb628648' 
  AND token = 'WJ+ZMKQUoYwrcuOaqSr8YafOXnbQRvC/t4z7Vpg3o6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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