SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5de059952add5344dcac8c28ef82b6f57e788ccd0c5982bf0e3ccbf5b72be818' 
  AND token = '/mwGhZl8fWsgtL6ce+NB3LlapI6AwN3A0Ij0bXOGvo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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