SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '37254f056f015bd2f4abbb7128292df6b24a798460d92866615b782beaf4bfff' 
  AND token = 'gq/sCXo9VufbsfJ7dpx1tzUsacyznBvScT9mvhRx3KQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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