SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e73e7e96403438fa3182601af16d17506e40439167fbffe56439b2c8bffc47b7' 
  AND token = 'jpAz+Ru1ZFswim7o8Hoo9KJUzj1Hh2g4fuHQYU17wjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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