SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e45962a79b95e64d58429c7a449f09b1a81848ff01b3b1f76e5622a472b1f10' 
  AND token = 'tfhR/+Ve3kW1zIJHfW9iIqGkAVeZde2EE/jGbyppKUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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