SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36dfb4a705f6f80dca6c1a5b4fc78c2e69858273acdbee219734f2f2f9af08a5' 
  AND token = 'AWagb/8Z37pFvQjjNXmGisV8sKOG+eFG/aLj1zBvPPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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