SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe63fb01a2fe5df481c58444b861fb20145c12ff6b74a4168fb7114039e40fb2' 
  AND token = '2GszE/VS4HRR6/TIJ37hIUGb42ArThhmuSFHyLVADIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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