SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c93e7a03e809de39e19bbeb29de9bdba0c144d7bd3c5ac8cb40413dad925c81e' 
  AND token = 'Gv6ui8zP3Wtc+FAhVTeXdd/AA/bUqBOAjTBsphofWRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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