SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4681fa65d86d132fd106f31bca682661f28bb2b1722905944276abb8aa9060e2' 
  AND token = 'ceKJ6FmHabmDC1pmwr7Vgncp+LTpU6UAD7o/jgSyVBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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