SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '016bfdd6a9353ef0aa42345d0226ee71bfa4579d29d70905302c875e6e2621b0' 
  AND token = '19ynNHIuxsgWHpIT3/jFOIFcXZ4fLqkEXeSdGRw+by0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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