SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c0fde04174b71af8935583480bff0c9538b22749a5d265582e2705bb51893758' 
  AND token = '/r60Wqa1WFvdvQdFimgS4YN2S0OXyrB20KBZ/E/VHCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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