SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a003ae766c9bc81fb5488c1b3947002192ec872ce0935b1595baa827f909eb87' 
  AND token = 'unS3BMuR+cJbNQsL1FoYhbtxa6CTTPGtUc1OzhA+viI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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