SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd99cedcb7d623512f94081d2b9f796300dbdf0f01c2e1ea45459eaa4bc393f3e' 
  AND token = 'FSIOnjIHTPxCze7Qk7dBWDOdbfBvZcz53WGI5nE5hvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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