SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d5fda6f9bfc88d81eb44cd59f0132eb24e73a1a1fe77ac0eadc3daaf78751c4' 
  AND token = 'tmwY2AASkfWMGN2bBygJMWeUKeJMf+lzfhT6IZi3lOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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