SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5adad29c814516e5f0a8bdecdfccddd73ce559f868bfa3b6f215bfe199670c86' 
  AND token = 'sXUPfRs7xRgSoZ4C49QqLmzu0G/+GpZc3s+2vn3FvGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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