SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'defe9c897dbb2c7a920db0fc0d81e2b47b49780a16fcd9010dc47bfaef52a627' 
  AND token = 'nLayaKUcBSfICEBoPluj73cT2T8ikr6MThfrYCK9zWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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