SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1897922e087063f0f0f298b97c3d20676f6e9f1139392397f85be788b180ef2a' 
  AND token = 'xze/PaaKNhmuuP71eMKft1/lH4ShVO9MlxgBMoeMq7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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