SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c5e3b1508c94ddf5597a52a89dc6e2951bdb952a304709b097034685c35575d' 
  AND token = 'Z42KdlMs6NHOzxpeuagndx0ubEPea3e6Z1TwHwoMHUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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