SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '910e4191e1442a24488f5819dcf972b366e466fdd5c6cca85bfe270a0e2473be' 
  AND token = 'uisI3kwpiPQCa96sAoso9TbyebS6tLpZogyKLtwrGU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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