SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd14247c4a2657f2f8c2912e70635024b646ff6b9d774e96e87fd38d92bd792f1' 
  AND token = 'qJWMe+/U70oDp4ZF1xj/n043IhNpEBdzdQUHN5sTgow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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