SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc9826df1eac2fe7e016de94b6c911cc5b1fdd5bf7821bd0ac871d1f1cc6543' 
  AND token = 'T/X9ZM2XVKZK+spuISeEBNSnd/13lzbHOSoWw1wXIRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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