SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e3260ff17c17b56106a123e0740ba530ef3922148732f3676967dbe630fc468' 
  AND token = 'jWRaSqxAOnJV5ZKKnqctyN9mtcUnGGFKKn9YkcddeKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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