SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f3fe59f31284ac1798eb658eaac8c0211059042f0256bd10e5f19d652d2462b' 
  AND token = 'XEZ5tbVEm2UqXbQfz1Shy3HXJ3ro36gFUJbdyWFCzgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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