SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd12380e75dda9d083ae06ac67b143f63caa891eccfe651d1eb90cfd16ba7abc1' 
  AND token = '8E6XGPKapGFeUoPpOzscW/3KwHDgLh14HfQEECd5wUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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