SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8adf1137fb93841f9ffb3ac6c4d6d114eb29a20ffc2245fccf4c86b1eec45314' 
  AND token = 'U5BsjLa5+uJtW/L6rOjkiMH8K7EqWX33FbwTSomFuzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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