SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a4974f5a14bfde8afd96aca9296653f42b102d7d4518e2d3c29965f994aa5b5' 
  AND token = 'dRgIcG7xjDl8NPkGXa/YZRBQNjXCJP4kwuKKOs6fBB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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