SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc23f35783c7ef87fdf2566669766c9bf6db9b5828590ff782a8205066fd62fb' 
  AND token = 'Y/e5+JMxgWLerOR+L3TcuS0BXp+vnEZjSmLG89iPXOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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