SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6df72be5bba0c3df3e159735dbbda68274f6460aa17247db1be18e31d3aaaa0b' 
  AND token = 'G7s1PjUf1R8qftJEXNA+Yj8uGUN7oBJp292CbQU5Tbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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