SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c91abc2c2f1726660b3705c84be98487435920a39144a67427d83c8a6fb3f95' 
  AND token = 'IKCet2MpTgdEipE74CB8wP8BgQ6Dy7j009HlPCIkqq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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