SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75f63688c6bbd6d652dd42db75b372db86df3280f5686aa240952745ce2ea094' 
  AND token = 'nuZPCj0JNAxDzshzctOsGFi8fJVLeAglxgfugsrQjrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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