SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '875450afc6407fd6c8ae40ee66fe966d531287c1c933d81149cb2781d818f2a6' 
  AND token = 'ygbbf91qxtJ4I7OJdJygiq9NHcu2i6kOHakkZvP9Cmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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