SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaa85833d406c22040e46cf52258d73fcb005ee1b5b567417ba884a61130fa71' 
  AND token = 'N97cqVfoIAIBiPAgp7xV89gOuYgCJDQB4xusQC810mU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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