SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1ca76b8dcb435728c7b4b8f4df2b88567918bec1a3a306e20637546c7458e81' 
  AND token = 'j1bITHdI5MG04rnDI+FjFtIqmSmTwMpkwqP419D2fpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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