SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82e8e4c442ba391086b3941a2fca5cae0afc8b2a369fe5678b6aa5718cf399a0' 
  AND token = 'UrDjldptTE1P7iLAjsVB9XH8DVgWyr91m4MlRC9BVuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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