SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a90bc574dfe6e3113112f623fc41b7ba071aa9d83a65a7b5920cb7a4bbe1f33f' 
  AND token = 'ignk+GetvfGW4G2q+OvP/qNC9bnGM/sWUoiw03RzqRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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