SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f2171ed4bdfd4a12bcee91c78df38adc3d51933ffe8509500d52b5dcba762b1' 
  AND token = '+ynT/F8z5tq0dpyim9nBjAkTaq33Ughg0sCobJWuIZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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