SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ac480119bb32a1af1c16d2bbe25cc9a4e675b3e2c6a3f3f7c9ef4551822a9b9' 
  AND token = '7OFsBSlQT0v9OxyQ2B1DSCGUOVL38aW29g3PwTKJSkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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