SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55fafa63c2ac7f9e50d255854f1dcfcda8ae72db93072e341fd430670d9c7854' 
  AND token = 'y46kOsTRu21M+LQLPni4ttpxrZjyw9zZScQJXZPAo90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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