SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd81e89dc54acf74347683a7c8087e1eb98550456ff2013b16ea717264deba9ff' 
  AND token = 'hsKdEeiL1DpnsZuKPcGonYvEzTZRNwkGfkTO97b3/8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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