SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a3af95c90b7e4a10228315beb641b8a10623d780bc6bb24851b990b94326e8f' 
  AND token = 'baMKqYvxF+X8x/EOkXnifS7B5IcG/sonxuVTWnkF+HE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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