SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7019e83b822da1c666a312aa47f40fb954bdc252bea1baeeeb8f8c8f3335b4c' 
  AND token = 'kAcruQN4RdhqPhQikKXInMfWK5Rm7OESYFsNYt8bALw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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