SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '334d0ad78733f2e89adb5040e4748968a6a6343d417b718528e115436e986c8c' 
  AND token = 'gDAmCVBb6E9aygEI42yLl+VTurej3rCaasO5n+CAcTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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