SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b9532cb1614f771cb5185db154539ed22e506d76e53a73f3243372ca11dc65b' 
  AND token = 'BADLdLDFsyjI+hArsHCckizE2UE8Sil8BccH3eFCzbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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